1. Field of the Invention
This invention relates to the manufacture of optical communication components and, in particular, to such manufacturing processes employing a germanium compound.
2. Art Background
The use of optical fiber communication systems has increased dramatically in recent years. This increase is not only likely to continue but the rate of increase is likely to substantially accelerate. Thus, there is great promise that a substantial quantity of optical components and, in particular, optical fiber will be manufactured in the near future. It follows that a reduction in cost of such items would be quite significant.
Presently, optical components such as optical fibers are being manufactured through a sequence of manufacturing steps which include the reactions of a silicon containing gas, such as silicon tetrachloride, and reactions of a germanium containing gas, such as germanium tetrachloride, to form a glass with suitable optical properties. In such processes generally the effluent from the induced germanium and silicon reactions are vented to the atmosphere. Such effluents typically include a significant amount of particulate as well as gaseous materials. Indeed, a significant amount of particulate matter is expected since the object of the thermal reaction is to produce glassy materials and since particulate incorporation into the glass structure being manufactured is relatively inefficient. For example, generally in typical manufacturing processes SiCl.sub.4 reacts with O.sub.2 (as in the MCVD process described in J. B. MacChesney, "Materials and Processes for Preform Fabrication-Modified Chemical Vapor Deposition," Proceedings of IEEE, 68, 1181-1184 (1980)) or O.sub.2 and H.sub.2 (as in the soot process described in P. C. Shultz, "Fabrication of Optical Waveguides by the Outside Vapor Deposition Process," Proceedings of IEEE, 68, 1187-1190 (1980)) or as in the VAD process described in T. Izawa and N. Inagaki, "Materials and Processes for Fiber Preform Fabrication-Vapor Phase Axial Deposition," Proceedings of IEEE, 68, 1184-1187 (1980)) to produce particulate SiO.sub.2 with close to 100 percent efficiency and with approximately 50 percent incorporation of these particulates into the glass body being fabricated.
The cost of optical fibers produced by manufacturing processes including particulate forming methods has decreased significantly as the volume of optical fiber use has increased. However, since the use of optical fibers is expected to substantially accelerate, further decrease in costs not associated with mere economies of scale would be desirable.